1. Field of the Invention
The present invention relates to a mobile communication terminal, and more particularly, to a system and method for changing a talk group of the mobile communication terminal, which improves the user convenience of a PTT service.
2. Description of the Related Art
Currently, many mobile communication terminals on the market function as more than just wireless communication devices. For example, some mobile communication terminals include advanced functions, such as a camera function or a multimedia function, in addition to a wireless communication function. These advanced functions have become more popular due to enhancement of display units of the mobile communication terminals and realization of high speed communication. Nowadays, it is nearly standard for a mobile communication terminal to include a high resolution camera and an LCD (Liquid Crystal Display) screen.
An additional function that has been developed for use in mobile communication terminals is PTT (Push To Talk). Like a walkie talkie service, a PTT service is a half-duplex, one-way communication method, by which only one call party can transmit at a time, providing a One-to-One or One-to-Many voice communication service.
Full-duplex communication allows simultaneous, two-way voice communication. In contrast, in half-duplex communication, such as in a PTT service, only one party can be designated as a speaker at a time, and every other party must be designated as listeners. An apparatus supporting a PTT service of a mobile communication terminal in accordance with the related art is described below with reference to FIG. 1.
FIG. 1 illustrates the operation of a related art system that supports a PTT service of a mobile communication terminal.
As shown in FIG. 1, the related art system supporting a PTT service of a mobile communication terminal includes: a mobile communication terminal 10 that sends a message requesting a change of a default talk group set by a user; a base station 20 that transmits the sent message; and a PTT server 30 that sends a message approving the change of the default talk group, in response to the message transmitted by the mobile communication terminal 10.
A related art method for supporting a PTT service of a mobile communication terminal is described below with reference to FIG. 2.
FIG. 2 is a flowchart illustrating a related art method for supporting a PTT service of a mobile communication terminal.
As shown in FIG. 2, the related art method for supporting a PTT service of a mobile communication terminal includes sending a message requesting that a default talk group be changed from a first talk group to a second talk group (S21); in response to the request, receiving a message approving change of the default talk group from the first talk group to the second talk group (S23); and, in response to approval, changing the default talk group from the first talk group to the second talk group (S25).
Initially, information identifying a plurality of talk groups is provided to and stored in the mobile communication terminal 10 and the PTT server 30, for example, by user input. Subsequently, a user selects one of the talk groups as a default talk group.
Thereafter, when the user desires to change the default talk group, the mobile communication terminal 10 sends a message requesting a default talk group change to the base station 20, and the base station 20 transmits the sent message to the PTT server 30 (S21).
The PTT server 30 sends a message approving change of the default talk group to the base station 20, in response to the request, and the base station 20 transmits the approval message to the mobile communication terminal 10 (S23).
Upon receiving the approval message, the default talk group is changed from a first talk group to a second talk group (S25).
However, a disadvantage of the above-noted related art system is that changing a default talk group from a first talk group to a second talk group requires a user to manually select the change of the default talk group.